clocksource/drivers/davinci: Avoid trailing '\n' hidden in pr_fmt()

pr_xxx() functions usually have '\n' at the end of the logging message.
Here, this '\n' is added via the 'pr_fmt' macro.

In order to be more consistent with other files, use a more standard
convention and put these '\n' back in the messages themselves and remove it
from the pr_fmt macro.

While at it, remove a useless message in case of 'kzalloc' failure,
especially with a __GFP_NOFAIL flag.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200409092543.14727-1-christophe.jaillet@wanadoo.fr